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Electrification wires now powered up

By Matt L, on September 9th, 2013

Following the weekend rail shutdown, Kiwirail have now been able to complete and liven up the wires between Wiri and Newmarket (inlcuding Onehunga). As such they are now kicking into higher gear warnings about live wires across the network.

A safety campaign has been launched this week warning Aucklanders they won’t get a second chance if they get too close to the overhead wires which will power the city’s new electric trains.

The first of Auckland’s new electric trains has now arrived in Auckland. Over the coming months these will be tested around the network in preparation for train services in 2014.

The overhead wires are now live 24/7 and potentially deadly to anyone who may get too close or come into contact with them, says KiwiRail Project Management Office General Manager Murray Hood.

“As with ordinary power lines, the overhead power system on the rail network is built so that people doing ordinary things near them are perfectly safe,” said Mr Hood.

“Only reckless or mischievous behaviour poses a danger.

“Sadly, experience both here in New Zealand and overseas shows that some people ignore all safety advice and take risks with serious and usually fatal results.”

The overhead wires that will power the trains carry 25,000 volts, which is 100 times more powerful than that used in homes.

“You do not even need to touch these wires to be electrocuted – electricity this powerful can arc or jump across gaps so it is important to keep away and make sure anything you are carrying is also well clear,” said Mr Hood.

“So it is critical that the public must treat these lines as live and extremely dangerous at all times.”

An awareness campaign to get this message out has been developed by KiwiRail, Auckland Transport and Transdev – the three organisations which deliver commuter rail services in Auckland. Launched this week the campaign includes billboard, radio and newspaper advertising as well as a video available on YouTube and Facebook. A link to the video can be found on the KiwiRail website – www.kiwirail.co.nz.

“Transdev is tremendously excited about this new era for Auckland rail but it’s vitally important that everyone who travels on or near the train tracks heeds these important warnings about electrified overhead wires,” said Transdev’s Electrification Programme Lead Mike Yeoman.

“You can help us share the safety message. We encourage parents to talk to their children about staying well clear of the overhead wires and taking care around trains and stations, the rail network is no place to play.”

There have been several incidents on the electrified section of the North Island Main Trunk railway line that runs between Hamilton and Palmerston North in recent years.

“Invariably, these have all involved young men trespassing on the rail corridor and getting too close to the overhead wires. At best those that survived received serious burns,” said Mr Hood.

In 2003 a young male trespasser died after climbing on top of a stationary train in a freight yard in Hamilton. And in 2007 another trespasser received serious burns, again after trespassing in the same area.

The wires have meant the introduction of height restrictions at the 31 level crossings on Auckland roads within the electrified area. However, most road users will not be affected by these height restrictions, as most vehicles and loads would not exceed them.

Most level crossings will have a height restriction of five metres, however 11 crossings will be lower at 4.25 metres. Roadside signs will warn of the presence of wires and display the height restriction at each level crossing.

Motorists with loads exceeding the height restrictions will need to apply to KiwiRail for written permission to use a level crossing.

All I can say is that those lines are extremely close to some of the traffic rail overbridges ………I have been told these can arc discharge if you get within 1 m – one would assume that in areas where this distance would be easily accessible some sort of insulation or other safety guards would be in place ………one can hope ………No doubt we will find out if that’s not the case

KiwiRail, AT and NZTA to their credit have all gone to extreme lengths to protect against inadvertent contact. Clearance is the basic method, as required by international standards. These include the screens mentioned above, or vertical screens such as on the Orakei bridge, anti-climb devices, fencing etc. In addition, metallic parts of the screens are bonded to the guard conductors (across and under bridges, designed to catch any stray pantograph or contact wire), which in turn are bonded to the traction earth wire and/or to rail.

Warning and danger signs are placed on all masts and screens too, but ultimately you can’t prevent total stupidity.

Yes you would have to be stupid but there are stupid people out there. As the press release from Kiwirail notes, there have been incidents even in NZ. A search of youtube will find some fairly shocking examples (excuse the pun)

As other contributors have noted, you may be astonished at just how stupid people can be. There have been overhead electric lines on British railways for decades and yet still there are kids who think it would be jolly good fun to drop tinsel or bits of wire on the lines from over bridges. The consequences are as predictable as they are distressing.

In the end you cannot teach the congenitally ignorant. Also predictable are the shock, horror condemnations of Kiwirail we will be getting from the media.

Rather a lot of years ago I had a holiday job at Telecom (or the Post Office in those days?) writing some software to model how the currents in the Palmerston North to Hamilton rail electrification would induce currents in telecom lines. The rail line and telecom cables ran in parallel in a lot of places and the induced currents could be dangerous for the telecom technicians. It was quite an interesting project for a student, and I assume that they’ve had to do something similar for Auckland’s electrification. I remember the equations involved imaginary numbers, which is the one and only time I’ve encountered them since being taught them in secondary school.

The NIMT electrification also forced NZ rail to run a fibre alongside the track to replace their copper based communications circuits that traditionally ran alongside the rail line, the induced current from the 25KVA basically made the copper circuits useless,

My software only modeled the induced current and had nothing to do with mitigation, but one of the engineers mentioned fibre as a option. At the time fibre was fairly new. Near my work area was a lab where the telecom guys were working out whether they could work with it in the field. It’s one thing to splice fibre in ideal conditions… they had to figure out if a guy sitting in a hole in the road could splice the stuff while it was raining. They gave me a meter length of the stuff to show my friends who were also studying computer science.

These days pretty much all the telecoms trunking is done over fibre, and it’s only the sections from cabinet/exchange to kerb which are copper. And the fibre laid by NZ Rail turned into a backbone for Clear (yes, all the way back then). Don’t think there’s any telecoms copper following the railway lines now.

Fibre splicing tech has got a hell of a lot more sophisticated, too. These days it’s mostly gel-filled terminators which handle the joins by way of a special electronic machine, keeping water out of the join very nicely. Much more reliable than the old hand-ground glass termination, that’s for sure.

Fibre jointing is generally carried out of the ground as each of the joint pods have a loop of fibre allowing work to be carried out inside the rear of a van . Not too sure where the ‘gel-filled terminators’ are used. Those I work with are dry heat shrink splice protectors held in trays inside sealed joint pods.

Telstra acquired the right-of-way (and the physical cable) along the rail lines when they bought Clear, but I don’t know if they still use them. On the other hand, the National Broadband Map shows a piece of fibre clearly following the Raurimu Spiral…

Ah, the good old EPR (earth potential rise) in copper, obi! Even power cable faults used to fry Telecom cables frequently. But as others have said, fibre is now the order of the day, although some of the older fibre cables have copper screens that require mitigation.

It was a long time ago, but I vaguely remember that you could theoretically shock farmers if their fences ran parallel to the electrified rail lines for long enough. It struck me as a cool way to get free electricity if you wanted to exploit the situation.

Looking back, it seems mad that they trusted this to a nineteen year old university student, working part time in the holidays. There were no project managers, testers, business cases, or any of the other overhead that drives IT costs up these days. I did have a go-to mathematician I could consult to check that the formulas I was using were all right. It was written in Pascal on a funny HP computer that had a built in screen and a sort of dial device that you spun to move the cursor.

You certainly get some induced voltage from the Transpower 110kV line onto the Onehunga contact wire when dead, but not much.

On your other point, I was just thinking the other day how much responsibility my colleagues and I as junior engineers were given in the “old days” compared with today. In my (jaundiced) view, way too much specialisation takes place too early now, coupled with the overhead you mention. But it does mean that we oldies can still carry out a reasonable sized project (say $10-20m) from design to commissioning without much outside help, and complete it on time and within budget.

Awful. I’ve spent a bit of time in Jakarta, where you see hundreds of youth scrambling onto the roof of a train every time it stops. It’s quite something.

They considered putting suspended concrete balls to knock them off, but thankfully this plan was squashed, and policing increased instead. Even with enforcement, tens of people are killed every year through falls and electrocution.

DC has a much higher potential (I think that’s the word) than AC. 1.5kV DC can arc a lot further than 1.5kV AC. And the nature of DC vs AC means DC is more dangerous at a given voltage because it won’t throw you clear. In either case, if you make contact with the lines you are unlikely to survive.

Matt C, high voltage is more likely to throw you off, but with serious burns leading to amputation. Low voltage, having less energy, is more likely to hold you on (depending on the current) and is likely to trigger ventricular fibrillation resulting in death. DC requires higher currents than AC for the same effect.

On the subject of Transport does anyone know what has happened over the rollout of new HOP card for the buses that was supposed to happen a few days ago. I know they released a notice saying it had been delayed. But since then nothing. I have a horrible feeling it isn’t going to happen this year now. Anyone have update?